Mechanisms Targeting the Unfolded Protein Response in Asthma.

Lung cells are constantly exposed to various internal and external stressors that disrupt protein homeostasis. To cope with these stimuli, cells evoke a highly conserved adaptive mechanism called the unfolded protein response (UPR). UPR stressors can impose greater protein secretory demands on the endoplasmic reticulum (ER), resulting in the development, differentiation, and survival of these cell types to meet these increasing functional needs. Dysregulation of the UPR leads to the development of the disease. The UPR and ER stress are involved in several human conditions, such as chronic inflammation, neurodegeneration, metabolic syndrome, and cancer. Furthermore, potent and specific compounds that target the UPR pathway are under development as future therapies. The focus of this review is to thoroughly describe the effects of both internal and external stressors on the ER in asthma. Furthermore, we discuss how the UPR signaling pathway is activated in the lungs to overcome cellular damage. We also present an overview of the pathogenic mechanisms, with a brief focus on potential strategies for pharmacological interventions.

Effect of Cerium Oxide Nanoparticles on Oxidative Stress Biomarkers in Rats' Kidney, Lung, and Serum.

Background: The present study aimed to evaluate the effects of different concentrations of cerium oxide nanoparticles (CONPs) on the oxidative stress (OS) status in kidney, lung, and serum of rats. Methods: Male Wistar Rats were treated intraperitoneally with 15, 30, and 60 mg/kg/day of CONPs. The biochemical parameters, including total antioxidant capacity (TAC), total thiol group (TTG), malondialdehyde (MDA), SOD (superoxide dismutase), and catalase (CAT) were assayed in serum, kidney, and lung tissues. Results: MDA decreased, but TTG and CAT increased in serum by the administration of CONPs at 15 mg/kg. In kidney homogenate obtained from the group treated with CONPs at 15 mg/kg, TAC, TTG, and CAT significantly increased compared to the control group. However, CONPs at 15, 30, and 60 mg/kg significantly decreased MDA level compared to the control group. In lung tissue, CONPs in doses of 15, 30 and 60 mg/kg significantly decreased CAT activity, TTG and TAC compared to the control group, while in kidney tissue, CONPs at the concentrations of 30 and 60 mg/kg significantly increased MDA compared to the control group. Conclusion: Our findings suggest that CONPs attenuate OS in the kidney and affect the serum levels of OS-related markers but induce OS in the lung tissue in a dose-dependent manner.

Simultaneous Detection of Autophagy and Epithelial to Mesenchymal Transition in the Non-small Cell Lung Cancer Cells.

Autophagy is increasingly identified as a central player in many cellular activities from cell proliferation to cell division, migration, and differentiation. However, it is also considered as a double-edged sword in cancer biology which either promotes oncogenesis/invasion or sensitizes the tumor cells to chemotherapy induced apoptosis. Recent investigations have provided direct evidence for regulation of cellular phenotype via autophagy pathway. One of the most important types of phenotype conversion is Epithelial-Mesenchymal-Transition (EMT), resulting in alteration of epithelial cell properties to a more mesenchymal form. In the current chapter, we provide a method which is established and being used in our laboratory for detection of autophagy and EMT in lung epithelial cells and show the involvement of autophagy in modulation of cellular phenotype.

The NRAMP1, VDR, TNF-α, ICAM1, TLR2 and TLR4 gene polymorphisms in Iranian patients with pulmonary tuberculosis: A case-control study.

The innate immune response drives early events in Mycobacterium tuberculosis infection. Since human genetic variation is an important determinant in the outcome of infection with M. tuberculosis, we typed polymorphisms in the innate immune molecules, such as natural-resistance-associated macrophage protein 1 (NRAMP1), Vitamin D receptor (VDR), Tumor necrosis factor alpha (TNF-α), intercellular adhesion molecule1 (ICAM-1), Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) in a case-control study of pulmonary tuberculosis in Iranian population. We conducted an association study and included 96 patients and 122 matched healthy individuals. We used single ARMS-PCR technique to simultaneously genotype fourteen polymorphisms in this survey. Among all fourteen polymorphisms that were examined, three polymorphisms were significantly different between case and control groups. The TNF -308A polymorphism showed significant increase in allele and genotype frequencies among patients compared to control individuals [-308A allele: 19.3 vs. 9.4%, GA genotype: 28.1 vs. 17.2%, AA genotype: 5.2 vs. 0.8%; Corrected P (Pc)<0.05], and the TLR4 variant allele and genotypes prevalence (D299G and T399I) were significantly higher among patients compared to controls [DG genotype: 14.6 vs. 5.7%, Pc<0.05 and I399 allele: 4.2 vs. 0.8%, TI genotype: 8.3 vs. 1.6%; Pc<0.05], respectively. In conclusion, our data suggest that TLR4 (D299G and T399I) and TNF (-308G/A) genetic polymorphisms may influence the risk of developing tuberculosis after exposure to Mycobacterium.

TGFß1 genetic variants are associated with an increased risk of acute brucellosis.

OBJECTIVE: Cytokines play a critical role in the regulation of the immune response against brucellosis infection, and mediate production of many pro- and anti-inflammatory signals. Transforming growth factor-beta 1 (TGFß1), a powerful suppressive cytokine, inhibits macrophage activation and modulates T-cell function, and plays crucial roles in regulation of microbial replication and host responses to brucella. METHODS: The association of three polymorphisms in the TGFß1 gene (-509 C/T [rs1800469], + 868 C/T [rs1800470], and + 913 G/C [rs1800471]) in promoter, codons 10 and 25, respectively, with brucellosis infection was evaluated. This case-control study was performed on a total of 281 Iranian subjects including 153 patients with active brucellosis and 128 age- and sex-matched healthy individuals as controls. Genotyping for the TGFß1 -509 C/T and + 868 C/T variants was performed using tetra amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR). Also, the + 913 G/C polymorphism was genotyped using an allele-specific PCR. RESULTS: The results demonstrated that the TGFß1 + 868 C/T mutant homozygote genotype (TT vs CC), was a risk factor for developing brucellosis in the co-dominant and recessive models (odds ratio (OR) = 2.60, p = 0.023; OR = 2.602, p = 0.014, respectively). Additionally, the diplotype analyses revealed that TGFß1 codon 10 and 25 diplotype, TT/GG, was associated with an increased risk of brucellosis (OR = 2.49, p = 0.038). Other TGFß1 variants did not increase the risk of brucellosis infection. CONCLUSIONS: Our findings propose that TGFß1 + 868 TT genotype and TT/GG diplotype may confer increased risk of brucellosis in the examined population.

Regulatory T cell subtypes and TGF-ß1 gene expression in chronic allograft dysfunction.

BACKGROUND: Regulatory T cells have been suggested to have a protective role against acute rejection in allograft recipients. However, there is little information available about their contribution to chronic rejection process. The role of transforming growth factor-beta 1 (TGF-ß1) as a profibrogenic and/or immunoregulatory cytokine in renal allografts is also controversial. OBJECTIVES: To evaluate the frequency of CD4+CD25+CD127- and CD3+CD8+CD28- regulatory T cells in chronic allograft dysfunction (CAD) and to investigate the expression of TGF-ß1 in renal allografts. METHODS: Thirty biopsy-proven CAD patients were pair-matched with 30 stable graft function patients and a third group of healthy volunteers. Flowcytometry was performed on PBMCs to determine the frequency of CD3+CD8+CD28- and CD4+CD25+CD127- regulatory T cells in lymphocyt population. TGF-ß1 gene expression was assessed by Real Time PCR. RESULTS: The percentages of CD3+CD8+CD28- Tregs among renal allograft recipients was higher than healthy controls (p<0.001) since stable graft patients showed the most rates. The frequency of CD4+CD25+CD127- Tregs was lower in CAD patients than stable recipients (p=0.024) and healthy group (p=0.015). TGF-ß1 gene expression was greater in CAD patients compared to healthy group (p=0.03) but there was no significant difference between gene expression of stable graft patients and healthy volunteers. CONCLUSION: The negative association between the frequency of regulatory T cell subtypes and chronic allograft dysfunction proposes these cells as probable candidates for promoting allograft survival. Moreover, despite the immunoregulatory capacity of TGF-ß1, it is likely to be implicated in chronic damages of allograft tissue.

The association of interleukin-18 promoter polymorphisms and serum levels with duodenal ulcer, and their correlations with bacterial CagA and VacA virulence factors.

BACKGROUND: We analyzed the impact of interleukin (IL)-18 promoter polymorphisms on IL-18 serum levels in Helicobacter pylori-infected duodenal ulcer (DU) patients and healthy asymptomatic (AS) carriers. We also aimed to determine the association of the H. pylori virulence factors CagA and VacA antibodies with serum concentrations of IL-18 in order to elucidate any correlation between them. METHODS: Three groups of patients were enrolled: DU patients (67 individuals), AS carriers (48 individuals), and H. pylori-negative subjects (26 individuals). Serum concentrations of IL-18 were determined by ELISA. Patient sera were tested by Western blot method to determine the presence of serum antibodies to bacterial CagA and VacA. Genotyping of IL-18 promoter polymorphisms at positions - 137G/C and - 607C/A were performed by allele-specific primer PCR protocol. RESULTS: Our study revealed that serum IL-18 levels are positively influenced by CagA-positive H. pylori strains, so that maximum levels of IL-18 were detected in DU patients with the CagA(+) phenotype, regardless of the presence of the anti-VacA antibody. Regarding IL-18 promoter polymorphisms, the AA genotype and A allele at position - 607C/A were found to be significantly lower in DU patients than in AS carriers and H. pylori-negative subjects (p = 0.032 and 0.043, respectively). CONCLUSIONS: The IL-18 - 607C variant was associated with higher levels of serum IL-18 and an increased risk of DU. Moreover, our findings indicated that serum concentrations of IL-18 were influenced by CagA factor, irrespective of the VacA status, suggesting that high levels of IL-18 in CagA-positive subjects predisposes to susceptibility to DU.

Circulating levels of interleukin (IL)-12 and IL-13 in Helicobacter pylori-infected patients, and their associations with bacterial CagA and VacA virulence factors.

OBJECTIVE: The aim of this study was to determine the association of the Helicobacter pylori virulence factors, cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA) antibodies, with serum levels of interleukin (IL)-12 and IL-13 in H. pylori-infected duodenal ulcer (DU) patients and H. pylori-infected asymptomatic (AS) carriers in order to elucidate any correlation between them. METHODS: A total of 67 DU patients, 48 AS individuals, and 26 healthy H. pylori-negative subjects were enrolled in this study. Serum concentrations of IL-12 and IL-13 were determined by enzyme-linked immunosorbent assay (ELISA) method. Patient sera were tested by Western blot method to determine the presence of serum antibodies to bacterial virulence antigens p120 (CagA) and p95 (VacA). Serum concentrations of IL-12 and IL-13 were compared in 9 groups, including 4 AS phenotypes (CagA⁺VacA⁺, CagA⁺VacA⁻, CagA⁻VacA⁺, CagA⁻VacA⁻), 4 DU phenotypes (CagA⁺VacA⁺, CagA⁺VacA⁻, CagA⁻VacA⁺, CagA⁻VacA⁻), and 1 control group. RESULTS: The results revealed that DU patients positive for CagA, independent of the anti-VacA antibody status, showed drastically elevated levels of IL-12 (251 ± 43 pg/ml) when compared with the other groups (p = 0.0001). No significant difference was found between groups regarding levels of IL-13 (p > 0.05). CONCLUSIONS: Our findings indicate that in the DU group, the serum concentrations of IL-12 but not of IL-13 were influenced by bacterial CagA, independent of the VacA status, suggesting that high IL-12 levels may contribute to susceptibility to DU in CagA-positive individuals. These findings could possibly be considered to improve the predictive or prognostic values of inflammatory cytokines for DU, and also to design possible novel therapeutic approaches.